Extracellular vesicles (EVs) in plants have emerged as key players in cell‐to‐cell communication and cross‐kingdom RNAi between plants and pathogens by facilitating the exchange of RNA, proteins, and other molecules. In addition to their role in intercellular communication, plant EVs also show promise as potential therapeutics and indicators of plant health. However, plant EVs exhibit significant heterogeneity in their protein markers, size, and biogenesis pathways, strongly influencing their composition and functionality. While mammalian EVs can be generally classified as exosomes that are derived from multivesicular bodies (MVBs), microvesicles that are shed from the plasma membrane, or as apoptotic bodies that originate from cells undergoing apoptosis, plant EVs remain poorly studied in comparison. At least three subclasses of EVs have been identified in
- NSF-PAR ID:
- 10321065
- Date Published:
- Journal Name:
- The Plant Cell
- ISSN:
- 1532-298X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Arabidopsis leaves to date, including Tetraspanin‐positive exosomes derived from MVBs, Penetration 1 (PEN1)‐positive EVs, and EVs derived from exocyst‐positive organelles (EXPO). Differences in the plant starting material and isolation techniques have resulted in different purities, quality, and compositions of the resulting EVs, complicating efforts to better understand the role of these EVs in plants. We performed a comparative analysis on commonly used plant EV isolation methods and have identified an effective protocol for extracting clean apoplastic washing fluid (AWF) and isolating high‐quality intact and pure EVs ofArabidopsis thaliana . These EVs can then be used for various applications or studied to assess their cargos and functionality in plants. Furthermore, this process can be easily adapted to other plant species of interest. © 2022 Wiley Periodicals LLC.Basic Protocol 1 : Isolation of EVs from the apoplastic fluid ofArabidopsis thaliana Basic Protocol 2 : Density gradient fractionation of EVsBasic Protocol 3 : Immuno‐isolation of EVs usingArabidopsis tetraspanin 8 (TET8) antibody -
Abstract Extracellular vesicle (EV)‐carried miRNAs can influence gene expression and functional phenotypes in recipient cells. Argonaute 2 (Ago2) is a key miRNA‐binding protein that has been identified in EVs and could influence RNA silencing. However, Ago2 is in a non‐vesicular form in serum and can be an EV contaminant. In addition, RNA‐binding proteins (RBPs), including Ago2, and RNAs are often minor EV components whose sorting into EVs may be regulated by cell signaling state. To determine the conditions that influence detection of RBPs and RNAs in EVs, we evaluated the effect of growth factors, oncogene signaling, serum, and cell density on the vesicular and nonvesicular content of Ago2, other RBPs, and RNA in small EV (SEV) preparations. Media components affected both the intravesicular and extravesicular levels of RBPs and miRNAs in EVs, with serum contributing strongly to extravesicular miRNA contamination. Furthermore, isolation of EVs from hollow fiber bioreactors revealed complex preparations, with multiple EV‐containing peaks and a large amount of extravesicular Ago2/RBPs. Finally, KRAS mutation impacts the detection of intra‐ and extra‐vesicular Ago2. These data indicate that multiple cell culture conditions and cell states impact the presence of RBPs in EV preparations, some of which can be attributed to serum contamination.
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Abstract The scientific interest in cannabis plants’ beneficial properties has recently sparked certain interest in the possible functional characterization of plant-derived extracellular vesicles (PDEVs). Establishing the most appropriate and efficient isolation procedure for PDEVs remains a challenge due to vast differences in the physio-structural characteristics of different plants within the same genera and species. In this study, we employed a crude but standard isolation procedure for the extraction of apoplastic wash fluid (AWF) which is known to contain the PDEVs. This method includes a detailed stepwise process of PDEV extraction from five (5) cultivars of cannabis plants, namely: Citrus (C), Henola (HA), Bialobrezenski (BZ), Southern-Sunset (SS), and Cat-Daddy (CAD). Approximately, 150 leaves were collected from each plant strain. In order to collect PDEV pellets, apoplastic wash fluid (AWF) was extracted from plants via negative pressure permeabilization and infiltration followed by high-speed differential ultracentrifugation. Particle tracking analysis of PDEVs revealed particle size distribution in the range of 20 to 200 nm from all plant strains, while PDEV total protein concentration from HA was higher than that of SS. Although HA-PDEVs’ total protein was higher than SS-PDEVs, SS-PDEVs’ RNA yield was higher than that of HA-PDEVs. Our result suggests that the cannabis plant strains contain EVs, and PDEV concentration from the cannabis plant could be age or strain dependent. Overall, the results provide a guide for the selection and optimization of PDEV isolation methods for future studies.
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Abstract Background Brain tissue-derived extracellular vesicles (bdEVs) act locally in the central nervous system (CNS) and may indicate molecular mechanisms in human immunodeficiency virus (HIV) CNS pathology. Using brain homogenate (BH) and bdEVs from a simian immunodeficiency virus (SIV) model of HIV disease, we identified RNA networks in SIV infection and neuroinflammation.
Methods Postmortem occipital cortex samples were obtained from uninfected controls and SIV-infected subjects (acute and chronic phases with or without CNS pathology [SIV encephalitis]). bdEVs were separated and characterized per international consensus guidelines. RNAs from bdEVs and BH were sequenced and quantitative polymerase chain reaction (qPCR)-amplified to detect levels of small RNAs (sRNAs, including microRNAs [miRNAs]) and longer RNAs including messenger RNAs (mRNAs) and circular RNAs (circRNAs).
Results Dysregulated RNAs in BH and bdEVs were identified in acute and chronic infection with pathology groups, including mRNAs, miRNAs, and circRNAs. Most dysregulated mRNAs in bdEVs reflected dysregulation in source BH. These mRNAs are disproportionately involved in inflammation and immune responses. Based on target prediction, several circRNAs that were differentially abundant in source tissue might be responsible for specific differences in sRNA levels in bdEVs during SIV infection.
Conclusions RNA profiling of bdEVs and source tissues reveals potential regulatory networks in SIV infection and SIV-related CNS pathology.
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Abstract Small RNAs (sRNAs) of the fungal pathogen
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